Erstellen und implementieren Sie eine Chat-Anwendung mit Socket.io und Redis.

npm i express cors socket.io -D @types/node

import express from "express"; import cors from "cors" import { Server } from "socket.io"; import { createServer } from "http" const app = express(); const server = createServer(app); // create a socket server. const io = new Server(server, { cors: { origin: "*", credentials: true, } }); // listen to connections errors io.engine.on("connection_error", console.log) app.use(cors()) const PORT = 3000; server.listen(PORT, () => console.log(`Server running on port ${PORT}`));

npm i ioredis

/** /src/index.ts */ import { Redis } from "ioredis" if (!process.env.REDIS_URL) throw new Error("REDIS_URL env variable is not set"); const redis = new Redis(process.env.REDIS_URL); // listen to connection events. redis.on("connect", () => console.log("Redis connected")) redis.on("error", console.log)

io.on("connection", () => { // ... socket.on("create:room", async (message) => { console.log("create:room", message) const doesRoomExist = await redis.sismember("rooms", message.roomId) if (doesRoomExist === 1) return socket.emit("error", { message: "Room already exist."}) const roomStatus = await redis.sadd("rooms", message.roomId) const memStatus = await redis.sadd("members", message.roomId + "::" + message.username) if (roomStatus === 0 || memStatus === 0) return socket.emit("error", { message: "Room creation failed." }) socket.join(message.roomId) io.sockets.in(message.roomId).emit("create:room:success", message) io.sockets.in(message.roomId).emit("add:member:success", message) }) }

io.on("connection", () => { // ... socket.on("add:member", async (message) => { console.log("add:member", message) const doesRoomExist = await redis.sismember("rooms", message.roomId) if (doesRoomExist === 0) return socket.emit("error", { message: "Room does not exist." }) const doesMemExist = await redis.sismember("members", message.roomId + "::" + message.username) if (doesMemExist === 1) return socket.emit("error", { message: "Username already exists, please choose another username." }) const memStatus = await redis.sadd("members", message.roomId + "::" + message.username) if (memStatus === 0) return socket.emit("error", { message: "User creation failed." }) socket.join(message.roomId) io.sockets.in(message.roomId).emit("add:member:success", message) }) socket.on("remove:member", async (message) => { console.log("remove:member", message) const doesRoomExist = await redis.sismember("rooms", message.roomId) if (doesRoomExist === 0) return socket.emit("error", { message: "Room does not exist." }) await redis.srem("members", message.roomId + "::" + message.username) socket.leave(message.roomId) io.sockets.in(message.roomId).emit("remove:member:success", message) }) }

io.on("connection", () => { socket.on("create:chat", (message) => { console.log("create:chat", message) redis.lpush("chat::" + message.roomId, message.username + "::" + message.message) io.sockets.in(message.roomId).emit("create:chat:success", message) }) }

# syntax=docker/dockerfile:1 ARG NODE_VERSION=20.13.1 ARG PNPM_VERSION=9.4.0 FROM node:${NODE_VERSION}-bookworm AS base ## set shell to bash SHELL [ "/usr/bin/bash", "-c" ] WORKDIR /usr/src/app ## install pnpm. RUN --mount=type=cache,target=/root/.npm \ npm install -g pnpm@${PNPM_VERSION} # ------------ FROM base AS deps # Download dependencies as a separate step to take advantage of Docker's caching. # Leverage a cache mount to /root/.local/share/pnpm/store to speed up subsequent builds. # Leverage bind mounts to package.json and pnpm-lock.yaml to avoid having to copy them # into this layer. RUN --mount=type=bind,source=package.json,target=package.json \ --mount=type=bind,source=pnpm-lock.yaml,target=pnpm-lock.yaml \ --mount=type=cache,target=/root/.local/share/pnpm/store \ pnpm install --prod --frozen-lockfile # ----------- FROM deps AS build ## downloading dev dependencies. RUN --mount=type=bind,source=package.json,target=package.json \ --mount=type=bind,source=pnpm-lock.yaml,target=pnpm-lock.yaml \ --mount=type=cache,target=/root/.local/share/pnpm/store \ pnpm install --frozen-lockfile COPY . . RUN pnpm run build # ------------- FROM base AS final ENV NODE_ENV=production USER node COPY package.json . # Copy the production dependencies from the deps stage and also # the built application from the build stage into the image. COPY --from=deps /usr/src/app/node_modules ./node_modules COPY --from=build /usr/src/app/dist ./dist EXPOSE 3000 ENTRYPOINT [ "pnpm" ] CMD ["run", "start"]